Biggest losses: CU coaches thought 2009 would be a breakout sophomore season for Darrell Scott, who was ranked as the nation’s top HS tailback in 2007. Instead, Scott rushed for a total of just 95 yards last fall (85 of which came against Toledo) and quit the team during the week of the ninth game and is sitting out this season at South Florida. Having earned his degree, Demetrius Sumler also opted out. Scott, injury prone and lacking in fundamentals, never approached his hype and Sumler, though well-versed in the offense, lacked breakaway speed. Reliable fullback Jake Behrens, a good blocker with receiving skills, completed his eligibility.

Strengths: Junior Rodney “Speedy” Stewart, just a two-star recruit coming out of high school in Columbus, Ohio, beat out the bluechipper Scott for the starting job and led CU in rushing the past two seasons, including a best of 804 yards and nine TDs in 2009. Though just 5-6, 175, Stewart bench presses 400 pounds and can break tackles. Brian Lockridge, a fourth-year junior, has breakaway speed as a sub.

Weaknesses: There’s a conspicuous lack of size and experienced depth at this position. Stewart has battled injuries during his two seasons. And Lockridge, 5-7, 175, appears better suited to be a spot player rather than a featured back. A star of the spring game, Denver East walk-on Quentin Hildreth, also is under 5-feet-9.

What to look for: To keep Stewart fresh, CU needs contributions from one or two of the true freshmen. The Buffs certainly could use the size of Allen in short-yardage situations. He also appears to have good hands and could flare out for a quick pass in the flat. Tony Jones has instinctive open-field moves that can make linebackers miss. Along the lines of Stewart, his signing might turn out to be a coup.